A manufacturing technology of a chip LED device generally includes procedures of manufacturing a circuit board, die bonding, wire bonding, encapsulating, scribing, testing, taping, and the like.
With reference to FIG. 1, which is a side-viewing diagram illustrating a structure of a circuit board 1 obtained by an existing manufacturing technology of a chip LED device. The circuit board 1 is formed by combining top layer copper 10, middle layer BT material 11 and bottom layer copper 12. In the process of manufacturing the circuit board 1, to realize electrical connection between the top layer copper 10 and the bottom layer copper 12, a via hole needs to be drilled in the circuit board 1 and copper 14 is plated on an inner wall of the via hole, and then the top layer copper 10 and the bottom layer copper 12 can be connected by the copper 14 plated on the inner wall of the via hole. In the process of encapsulating, the circuit board 1 generally is covered by an encapsulation adhesive in a manner of molding, and an encapsulation adhesive layer is formed to seal and protect an installed chip on the circuit board 1. However, since uncured encapsulation adhesive may flow out downwards along the via hole in the process of encapsulating, the via hole needs to be completely plugged firstly by resin 15 in the previous process of manufacturing the circuit board. A thickness of the resin 15 plugged in the via hole is often slightly larger than a depth of the via hole, and both ends of the resin 15 protrude from the via hole.
FIG. 2 is a side-viewing diagram illustrating a structure of an existing chip LED device. FIG. 3 is a rear-viewing diagram illustrating an existing chip LED device. With reference to FIG. 2 and FIG. 3, the chip LED device formed after the process of dicing still has the resin 15 in the via hole of the circuit board 1. Since a lower end of the resin 15 is beyond a lower surface of the bottom layer copper 12 and a thickness of the copper 14 is generally only 10 μm, the lower end of the resin 15 is easy to be collided by an external force in subsequent processes of testing and taping, so that a combination part between the resin 15 and the copper 14 is broken, which may result in drop out of the bottom layer copper 12 that serves as a bottom electrode of the chip LED device and cause product damage. In addition, the resin 15 may also cause a problem of poor contact of the bottom electrode of the LED device, thereby resulting in misjudgment of a testing result, reducing production efficiency and influencing a usage of patches of the LED device.